Plug-in relay



Dec. 8, 1953 H, E, SEATON 2,662,135

PLUG- IN RELAY Filed July 28, 1948 5 Sheets-Sheet l l /fqi @/5-5/ f' n J/ 75 @Y Y@ 4 INVENroR. Q2/oa E 5gg/ZZ@ H. E. sEAToN PLUG-IN RELAY Dec. 8, 1953 5 Sheets-Sheet 2 Filed July 28, 1948 Leg ILT

A A A INVENTOR. lafaz, lkw, QQ/@WMM H. E. SEATON Dec. 8, 1953 PLUG-IN RELAY Filed July 28, 1948 f3 Sheets-Sheet 3 INVENTOR. Hamid T .-@Qzom BY@ a l rgmuw Dec. 8, 1953 H. E. sEAToN 7016i /Olb 5 Sheets-Sheet 4 INVENTOR.

Dec. 8, 1953 H. E. sEAToN 2,662,135

PLUG-IN RELAY Filed July 28, 1948 5 Sheets-Sheet 5 INVENTOR.

Patented Dec. 8, 1953 PLUG-IN RELAY Harold E. Seaton, Shelby, Ohio, assigner to The Autocall Company, Shelby, Ohio, a corporation of ohio Application July 28, 1948, Serial No. 41,029

(Cl. 20D-87 10 Claims. 1

The present invention relates to an electrical relay.

One of the objects of the invention is to obtain an extremely high speed of operation. In this regard, a more specific object is to obtain higher operating speeds in a multiple contact type of relay having a considerable number of moving contacts, and having considerable contact pressure established between the moving and stationary contacts. The preferred embodiment of my invention herein disclosed is ci' this multiple contact, high pressure type. In my improved relay I obtain operating speeds as high as approximately 6 to 8 milliseconds (.O to .008 second) or even higher, depending upon adjustments. The design or" relay in which I obtain these operating speeds has six moving contact lingers, and maintains a contact pressure of at least thirty grams in its energized position and in its deenergized position.

rlhis high speed operation is extremely important, or even essential, in certain situations, particularly exemplified in high speed calculating machines employing hundreds or thousands of these electro-mechanical relays and performing such operations as multiplications, divisions, additions, subtractions, and many other mathematical functions, at a rate of approximately 60 to 100 per second. The very fast operation is also very important in supervisory signaling systems, such as vvaterfiow and sprinkler supervisory systems; also in the supervision and remote control of equipment in steam power plants, hydro-electric power plants, and the like.

Another object of the invention is to provide a relay which will have this high speed operation, and will also have an extremely long life without failure of operation, at least from the standpoint or multiplicity oi operations. For example, my improved relay is designed to meet the requirement of loo million complete cycles of operation vvithout a failure, and the relay has met and exceeded this requirement in actual operation.

In attaining this high speed operation and long operating life, it becomes quite important to reduce the collection oi dust upon the contact surfaces to an irreducible minimum. This also applies to the silver dust or metallic dust resulting from the Wearing away of the contact surfaces themselves.

@ne oi the features of my invention of particular benefit in minimizing the collection of dust cn the contacts is the mounting of all of the contacts in vertical position, preferably side-by-side,

instead of being stacked on top of each other horizontally, as in conventional relays. Thus, ordinary dust and silver dust tend to gravitate off the vertical surfaces of these vertically disposed contacts. n this construction, the niagnetic circuit and contact operating mechanism are arranged to extend horizontally rearwardly from this bank of vertically disposed movable contacts. The relay is made of more compact construction by virtue of this horizontal disposal of the magnetic circuit.

Another feature o1" the invention which is of pronounced benefit minimizing the collection oi dust on the contacts is the fact that the relay is of the Window type. The relay is adapted for panel or cubicle mounting, and the front oi the relay carries an individual glass Window directly in iront of the vertically disposed bank of movable and stationary contacts. individual sight Window helps prevent the collecticn of dust on the contacts by cooperating with the panel in closing oli` the front of the banks of relays. This individual sight Window has the further advantages of enabling direct observation of the contacts and their operation to be had; and it also prevents external touching of the contacts.

Another object of the invention is to provide an improved plug-in or jack-connected type of relay construction. The movable contacts, stationary contacts and magnetic circuit all have mounting assembly upon a portable relay frame in the form of a small compact unit, which unit is adapted to have plug-in mounting in a separate socket frame which is secured tc the mounting panel and is wired on the rear side ci" the panel entirely independently of the separate relay unit. All electrical connections to the separable relay unit are extended to terminal prongs which project from the relay unit and are adapted to have plug-in engagement in terminal sleeves or sockets provided in the plug-in mounting frame. The individual sight window for the relay unit is carried in the iront of the separable relay frame. This plug-in mounting facilitates the operation of wiring the plug-in socket, and also enables different or substituted relay units to 'ce plugged into and out of operative positions almost instantly.

Another feature of the invention resides in having the spring ilexure of contact engagement occur substantially entirely within the movable transfer contacts, rather than in the stationary contacts. That is to say, the movable transfer contacts are capable of a certain amount ci' overtravel in each direction of their motion, i. e. when moving rearwardly into engagement with the normally open stationary contacts or when moving forwardly into engagement with the normally closed stationary contacts. Upon engagement with either' set of the stationary contacts, this overtravel is absorbed by fiesure of the movable contact :lingers in preference to iiexure of the stationary contacts. rihis flexed condition of the movable contact fingers maintains the desired relatively high contact pressure during the entire time that the operating armature re mains in either of its two positions.

In this regard, another feature of the invention resides in the provision of an improved con.- tact pressure spring arrangement, entirely separate and apart from the contact for taining the armature and movable contact fingers in their de-energised position. A further ture supplementary thereto is the provision of improved means for adjusting the pressure this contact pressure spring.

Another feature of the invention related to the above-described overtravel of the movable contact fingers is the provision of improved adjustable stop means for limitingr the momentary overtravel of the armature when released from the energized position. This adjustable armature stop may be desirable in some instances so as to prevent overtravel and rebound of the armature causing the contacts to bounce or chatter in the de-energizing operation.

Another feature of the invention resides in the provision of improved adjustments for adjusting the positions of the electromagnet and of the armature relatively to the movable transfer con tacts and relatively to each other.

My improved relay can be constructed of various types, such as (l) the ordinary single coil type; (2) the double coil type wherein one coil serves as a pick-up winding and the other as an electrical seal-in winding; and (3) the latching type wherein the contact actuating armature is mechanically latched in its energized position, and requires the energization of a separate unlatching coil for its release.

Other objects, features and advantages of the invention will appear from the following detail description of certain preferred embodiments of the invention. In the accompanyingr drawings illustrating such embodiments:

Figure 1 is a fragmentary front view of a mounting panel or cubicle in which my relays are mounted, and wherein Figure 1A shows a relay unit in its mounted position in the plug-in socket, and wherein Figure 1B shows the front face of the plug-in socket frame with the relay unit removed therefrom.

Figure 2 is a rear elevational View of the relay unit removed from its plug-in socket frame;

Figure 3 is a fragmentary View from the inside of the panel or cubicle showing the mounting of the socket frame in a substantially corresponding opening cut in the panel;

Figure fi is a side View of the relay unit (partly in section) preparatory to being inserted into the socket frame;

Figure 5 is a vertical sectional view through this socket frame, showing its mounting in the panel;

Figure 6 is a plan view of the separate relay unit, corresponding to a view looking down upon the top of Figure 4;

Figure 7 is an elevational view of a part of the relay unit, illustrating one step in the assembly of the contacts;

Figure S is a plan view of the contact spacing block adapted to be inserted between the two banks of stationary contacts;

Figure 9 is a front elevational view of this spacing block;

Figure 10 is a fragmentary view similar to Figure 7, illustrating the next step in the assembly operation wherein the spacing block is placed over the rear bank of stationary contacts, and the front bank of stationary contacts has been mounted in assembled relation to this spacing block;

Figure 11 is a vertical sectional View of this sub-assembly illustrated in Figure l0;

Figure l2 is a front elevation illustrating the next step of assembling the outer cover plate over the front side of the sub-assembly shown in Figures l0 and 1l;

Figure 13 is a side or edge elevational view showing this assembled relation;

Figure 14 is a side view showing one manner of mounting the movable transfer contacts;

Figure l5 is a similar View showing a different manner of mounting these transfer contacts;

Figures 15 and 17 are plan and front elevational views respectively of the electromagnet and armature sub-assembly in condition for securing to the sub-assembly shown in Figure 13;

Figure i8 is a detail sectional view on an enlarged scale, corresponding to a section taken approximately on the plane of the line IB-I8 of Figure 16, showing the manner of adjusting the position of the armature relatively to the electromagnet;

Figure 19 is a vertical, sectional View through the electromagnet, armature and contact iinger assembly, illustrating one form of adjusting means for adjusting the compression of the armature return spring;

liigure 20 is a fragmentary View similar to Figure 19, showing another form of spring adjustment and an adjustable stop for the overtravel of the armature;

Figure 21 is a similar sectional View illustrating another adjustable stop for limiting or preventing overtravel 0f the armature;

Figure 22 is a side elevational view, partly in section, showing my invention embodied in a latching type of relay, and

Figure 23 is a plan view of this latter embodiment.

In Figure 1J I have shown a relay (Figure 1A), and a mounting socket for a relay (Figure 1B), mounted side-by-side in a vertical mounting panel, cubicle wall or the like which is indicated fragmentarily at P. In the case of a calculating machine of the relay type, such as I have referred to above, there would be hundreds, or possibly thousands, of these individual relays disposed in closely spaced rows and columns in these vertical mounting panels or cubicle walls P. Figure 1A is a front elevational View of one of the relay units R mounted in its normal position in the mounting panel. Figure 1B illustrates the relay unit R. removed, this ligure showing in front elevation the plug-in mounting socket S which is iixedly secured in the mounting panel P for each of the relay units R.

Referring to relay unit it, this coinprses a rectangu front do c nposed of insulating ma' fis shown in liigure '4, this frame 33 comprises iront and rear frame sections 30a and 3M), between which are clamped canas or rows of movable contacts and coating stationary contacts. For-inea within front and rear frame sections Sta and 36D rectangwftr openings 3l which define a sight r g extending entirely through the mountg trarne from front to nach. Mounted in he front erige of opening 3i is a pane of lass or transparent plastic material which orins a sight Winslow through which can oe obvervecl the condition and operation oi the relay contacts. This pane of glass is removably held against a recessed retaining slioulrlcr in the iront section by retaining clips secured. to the mounting frarne 33 'oy screws 3P. The mounting of the relay unit R in the socket frame S establishes a dust-tight joint het .veen the lay unit and the panel i3, and. the sight 'icio-v establishes a clust-tight closure over the nt of the sight opening t i, nel hence clust cannot reach ne contacts from the iront of the ci cr- (3 ee o (LA (D relay. ii/"hors the relays are mounted on the vr 11Vical panels or cubicles, the interiors of these cuoicies are usually inacle dustntight as well.

Clainpec' oetween the iront naiv-es Elta and ich of the contact mounting frame Se are the bank oi movable contacts the baril; of contacts 3i?, and the hanlr or :ar contacts 3e (Figure fi). rFliese of contacts extencl vertically in the contact points banks visible thro the window Jer ends ci the inovaole conical connection with in prongs @la projecting rearwardly 'une adjacent to its upper eclge (i -gare il Similarly, the bank of iront sta tionary contacts (which are the normally closeel` contacts in the le-energiaeel condition of the relay) are provided with plug-in ngs Site which project in a bank from the oi the frame 35i adjacent to its lower edge. Similarly, the rear oanlr of stationary contacts (winch are the normally open contacts in the flacher- .ised condition of the relay) are provided with 1ug-in prongs 3%@ which project rearwardly iL the frame above the bari; ci prongs lilla.

of rearwardly projecting ple' l cl Sea are adapted for re- 2 .ug-in .iinal sleeves el, and unterl in horizontal rows in the Fig. 1B and Fig. 5). c ing frame together with its contacts S i, and Se, and. its plug-in prongs and constitute one suhassern`oly oi the unit Pt. Projecting rearwarclly from am 4. uflt sdm-assembly is anothe1 sub-asseinbly coinm p ing the electromagnet is and, its armature cil. This electroniagnet and arme/tur sulasly is carried between upper anol lower :nonnting brackets il and 53 which are provided with laterally projecting attaching alla These attaching ears are set into recesses i nei-l in L'lie rear freine section to the assembled traine ley screws pasa ,cg through from the front of the i A nie and hreatlng into holes in the attaching ears *la ano' I shall describe the details oi the electromagnet and armature sub-assembly after describing the socket frame S and the details of assembling the contacts in the relay trame Referring now to the socket frame S, it will he seen from Figure 5 that it is provided with a large rectangular opening 5! through which passes the electroinagnet Elli, armatore lf3 and the upper and lower mounting brackets il and 4t. This rearwardly projecting sub-assembly is adapted to pass through the opening 5i so that it lies substantially entirely on the rear side of the socket frame S. Formed along the top and. bottoni edges of the frazne S are flanges or lips 52, 52 which are adapted to abut against the front side of the mounting panel P. Extending across the upper portion of the trarne ilv is a relatively thick portion 53 in which is rnountefl the row of terminal sleeves il for receiring the plug-in prongs Slo. Similarly, extending across the lower portion of the socket frame is a thick portion 5t in which are mounted the two rows of terminal sleeves for receiving the plugin prongs and Figure 3 illustrates the preferred shape the opening E5 which is punched out in the panel for mounting the socket frame S. This opening conforms to the top and bottom edges of the thickened portions 5?; anol 5t, and intermediate these portions the opening is torinesi with side iiange portions Which cverlie the side margins of the soclret freine a distance to threaded. holes formeel therein into which thread mounting screws shown Figure 5, the mounting screus pass through the socket frame the fr t anti thus securely hold the socket 'traine in its position in the opening all of the panel. Th t rininal eves 'ne eyelet Ill, [i2 anni are preferably type, such being a well lrnown opening for each terminal sleeve or eyelet forinecl w li a recessed slot as to provide a cavity for t sides of the terininal sl eves i ttenecl in position. The expansion of the terminal sleeve into the slot Si prevents the terminal from turning, which is an advantage in manufacture, and in connecting soldering oi the wires to the terminal. Holes are puncheti in liattenecl terminal sleeve to hold anti clamp t1 fore soldering. Such v 'res are not it will be understood that they are c the rear ends or the terminals or eyelets fil-, and f2.3 on the inner or back of ti e panel The so et frane composed of any suitable insulating typically' represented by a material, phenolic condensation proouct, suoli as Bakelite.

As previously described, the mounting of the relay unit R in the socket S establishes a dust-tight joint between the relay unit and the panel P, and the glass sight window establishes a dust-tight closure over the iront of the sight opening 3l, so that dust cannot reach the relay contacts from the front or" the relay. More specically, the socket iranie S has sealing surfaces along the top and bottoni flanges ancL along the sides overlying the panel (Figure 3), which sealing surfaces on the socket frame abut coacting sealing surfaces on the outer side of the panel P, thereby forming a dust-tight `ioint between the mounting frame and the panel around the edge of the panel opening 55. Sinin ilarly, the back surface S2 oi the rear relay frame section 35h and the front surface Sii the socket frame S abut together coasting sealing sur faces, thereby a dust-tight joint between the relay unit it and the socket frame S. 'When the relay unit R is plugged into the socket frame S, the weight of the relay unit R, and other stresses incident to the support of such unit, are borne by the engagement of the plug-in prongs 37a, 38a and 39a in the plug-in terminal sleeves 4I, l2 and t, and oy the abutment of the back surface t2 of the relay frame section 3Q?) against ascenso the front surface t3 of the socket frame S, at the latter of the above described dust-tight joints. It will be seen that when the relay unit R is in this plugged-in position in the socket frame S, the elcctromagnet armature sub-assembly 45, 4G, and particularly the electromagnet a5, extends entirely through the aligned holes in the socket frarne and panel, so that it lies inwardly or rearwardly of the plane of the plug-in prongs and plug-in sockets and rearwardly of the two dusttight joints, particularly of the separable dusttight joint {i2-63. Thus, the weight of the electroniagnet to and the weight of the relay frame sections 39a and (itil) tend to balanceeach other on opposite sides of the plane of support, which plane of support is defined approximately by the plane of the plug-in prongs and sockets and the plane of tnc separable dust-tight jointV 52, 63. This substantially balanced relation avoids the possibility of anylong,r continued vibration loosening the engagement of the plug-in prongsin their sockets or accidentally separating the dust-tight joint 62---6S- Referring to the incre speciilc details of the rclay contacts and the manner. of their assembly within the contact mounting` frame 30, Figure 7 is an inner elevational view of the front face of the rear frame section 39h, illustrating the first step in the operation of assembling the relay contacts. Mounted in appropriate recesses in the upper part of this rear trarne section are the transfer contact terminals @lb to which are secured the movable transfer contacts 3l. Theo terminals Elli) have rearwardly bent upper ends which pass rearwardly through holes inthe frame section 3017 and constitute the upper bank of plug-in prongs ilu. l shall hereinafter describe the manner of securing the movable transfer ccntacts 31 to these terminals 31h.

Referring now to the lowerY part of, the rear frame section 3th, it will be seen that a rectangular cavity 154 is formed in the lower portion oi' this frame section, and assembled in this cavity is the bank ci stationary rear contacts 39. The lower ends of each oi these rear contacts are provided with rearwardly bent. extensions which pass through holes in the iranie section and constitute the bank of plug-in prongs 39a.

Disposed in cavities along the side portions of their-ame section 313D are upper and lower coil terminals bwand tfwhich are provided for.. the purpose of establishing electrical connection with the one or more coils of the electromagnet 45. The upper ends of the terminalsvare provided with plug-in prongs 65o (Figure 6) disposed at 5. opposite ends of the bank of plug-in prongs 31a. The lower ends of the lower terminals` 55 are likewise provided with plug-in prongs 66a (Figure 2), disposed at opposite ends of the bank of plug-in terminals 39a. The adjacent inner ends of these coil terminals t and 63 are provided with-rearw rdly projecting tabs 65h and 66h which extend back through the opening` 3| for establishing soldei-ed connection 'with the terminals ofthe electromagnet coil or coils.

The next step in the assembly operation isto set into the rectangular cavity Ella contact spacing block iii, shown in detail in Figures 8 and This block, composed of insulation, has a rear bank of cavities 69 for iittng over the stationary rear contacts 39. The front face of this blocl:y has a similar set of cavities Il for receiving the bank of stationary front contacts 38-` After the placing of the block 68 over the-rear contacts 39. thefront contacts ,38 are then assembled in their 7 cavities ll in the front face of the block, as shown inFigure 10. The lower ends of these `iront contacts 38 have rearwardly bent portions which pass through holes in the spacing block and in the rear frame section and constitute the lower bank of plug-in prongs 38a. The parts are now in the assembled relation illustrated in Figure 1l. The front cove-r section 39a of the frame 33 can now be assembled over this assembled relation of rear frame section and stationary contacts. As will be later described, this may take place either before or after the mountiiu,T of the movable transfer contacts 3i', depending upon the construction of these transfer contacts or any other preferred sequence of operation.

Figures li and l5 illus two diierent types of mounting for these movable transfer contacts. In Figure 11i the downwardly projecting terminal portion 31h formed. with a notch or slot 31o extending across the entire width of its liront face, Formed in the up nortion oi' the contact iinger El is an offset hump or rib Bld extending across the width of the ringer adapted for snug iitting reception within the slot or notch 3io. The hump or rib Sic-iris forced into firrn pressure engagement within 'the notch 3io by the pressure ci drawing the i ont traine section baci: into ti; it ritt-ing ent against the rear frame section i o hoizuontal width. oi' l caring; en-

rib and the notch rn'ily hold the Contact linger 31 against sidewise swiveline' movement relatively to the 'terminal portion 'in contact nrw-er mounting illusal rtlon Bib is ,rel donn lower, so as to project into the l ci' the mounting traine. diy projecting portion is the contact tn an aperture Blf adapted attaching screw 37g which passes aperture oli and threads into the ff "e mounting; screws i'ig are upper edge of the ow pane i e inserte:`

tll through the 'Moed hole o f prin-gx "re holds the forwardly against st' tacts Upon energlaation ci' t e het, the contacts are pulled rearwardly out oi' lent with the front contacts 3-3 and into lent with the rear con-- t"ots Suzi. i is directed to the ringed forbe contact spacing; block ecting contact dust and e or increasing surface gap length i .i Lacts. viewed in Figure a rid e 'l proget-ts upwardly from the 'top of the bloot: between i ,ch companion pair of iront contacts and contact dust cocu-.ring fron; t "l or" the contact points is ly an.r1 rearwardly by this ridge i upon the spacing block. This 'fe or 'i creates a longer insulating n betw i contacts and When a iu ay is required to operate approximately loll inillion complete cycles without failure,l it follows that there is a wearing away of the contact silver that causes a dust to collect on the spacing` block This dust, if allowed to collect on a horizontal surface, wouldin time electromag- Si? for the p rid' lend of this spring seats in a, depression I D4 formed in the back side of the armature 45. The spring is preferably tapered `with its smaller end at the front so as to avoid any possibility of the front portion of the springhaving any frictional drag engagement against the sides of the opening 81 in the oscillatory motion. of the` armature. The rear end of the spring bears against a centering head liti on the front end of an adjusting screw |06. The screw threads outwardly through the tapped bore of a nut V|81 which has la press rfitto the desired depth withinfthe opening 81. `The nut "l1 is of the self-locking type, such being a well known construction, by crimping therein a Afriction gland ring or retaining washer |08 which serves to frictionally hold the adjusting screw IDS in each of its adjusted positions within the nut M1. It `will be seen that the pressure of the spring til can be easily adjusted by inserting a screw driver into engagement with the kerf IBS in the end of the screw |96 and rota-ting it in the appropriate direction to increase or decrease the pressure of thespring. Figure '19 villustrates how the overtravel of the armature 46 in each direction of movement causes flexing of. the movable contact lingers 31, and thereby establishes the desired relatively high contact pressure and sliding or wiping action against both the front and 'back stationary contacts in the two positions of the armature. Normally, Ithe spring 8S maintains each movable contact vfinger 31 flexed forwardly in the -full line position illusf trated in Figure 19, and when the relay is energized the retractive movement of the armature flexes these movable contact fingers rearwardly into the dotted line position. I preferably construct and adjust the relay so that contact pres- F sures of at least 30 grams are obtained against both the front and back contacts 38 and 39.

Referring now to the manner in which the transfer contact lingers 31 are assembled in the relay, these contact fingers are threaded up through the slots |il|c in the Contact operating bracket I| The clamping or holding screws GS, 15, 1G and l1 are started but not tightened until after the transfer contacts have been located in their proper positions. After being threaded through the slots IEIe, the terminal ends. o! the contacts are then threaded in between the frames 30a and 3th until the silver tips of contacts 31 are positioned between the contact operating bracket |tl| and the stationary front contacts 38. It will be noted that due to the pressure of the armature spring 38, the bracket IUI now extends out through the opening 3|. This brings the slots |o|c in bracket nearly in line with the face or" frame 32o. Bracket IUI is then pressed inwardly until contacts 31 are positioned above and between stationary contacts 38 and 39. Contacts 31 are then pulled back in between stationary contacts 38 and 39 to their normal operating positions and aligning the offset humps '31d with the slots 31o in the parts 31a, or alignins the `holes 31]t with the tapped holes 31e for applying the anchor screws 31g. After this assembly operation, screws fie, 15, 1t and 1.1 are securely tightened. While this is the preferred manner of assembly of the transfer contacts 31,

it will be understood that the invention is not limited to this Asequence or manner of assembly.

`,In Figure 20,1 haveillustrated amodiiied construction which has the .two-fold featureof pro viding an adjustment for the armature spring pressure, and also of providing an adjustable stop for-'preventing overtravel of the armature. In this construction, the front end or the axial opening 81 is provided with an internal thread into which screws the 'threaded front end of a stop adjusting sleeve SIG. The compression spring -83 is confined within the bore H5 of this sleeve, and the front end of said spring acts upon the 'head HS of motion transmitting thrust pin II'I. Such thrust pin entends outwardly through a reduced counterbore in the end of the adjustable stop sleeve I |-4 and has its front -end bearing in a depression |04 formed in the back side of the armature t5. A stop washer IIS of shock absorbing material., such as rubber, leather or the like, is seated in the bottom of the -bore IIS, and the head IIS `of the thrusting pin is ynormally pressed against this washer by the spring 88. The rear end of the bore H5 is internally threaded at I2| for receiving` a Vspring pressure adiusting plug |22 which screws forwardly in 'this thread and adjusts the pressure of the spring 88. Screw driver kerfs |23 and |24 in the sleeve |11 and plug |22, respectively, provide for independent adjustments of these two elements. As stated above, screwing the plug |22 forwardly or rearwardly provides l'or adiusting the pressure of the spring 85. ilorewing the stop sleeve IM forwardly or rearwardly in the thread III provides for shifting the position of the stop vwasher I forwardly or rearwardly to avoid objectionable overtravel of the armature. In the spring return movement oi the armature, the thrust pin II is brought to a stop with a cushioned, impact by the cushioning stop washer I|9 and this prevents bouncing of the armature in such spring return movement.

In Figure 21, I have illustrated another modied construction in which overtravel of the armature in its spring return movement is positively limited by a positive stop rod |26. 1n this construction, the magnet core is provided with a front bore 81a and a rear bore 81h connected by a reduced counterbore 81o. The spring 88 is confined in the front bore 81a and bears against the back of the armature. The stop rod I2 extends through the armature and has a positive stop head |21 on its front end. A cushioning washer |28 of shock absorbing material is interposed between the head |21 and the front part of the armature. The stop rod |26 extends back through the reduced counterbore 81e and has threaded engagement in a self-locking nut |25. This nut is similar to the nut |01 of Figure 19 in that it is provided with a contained ring of resilient gripping material which causes the nut to frictionally bind upon the threaded rear portion of the stop rod |26. A cushioning washer 53| of rubber or other shock absorbing material is confined between the nut |29 and the bottom of the bore 81h. It will be seen that the rod |26 is adjustable to denne the outer limit of travel of the armature in its spring return motion, and it will be seen that this outer limit of travel is positively defined, but is cushioned bythe cush=n ioning washers itt and lill to avoid bounce of the armature.

described in the fore part of this specincation, the eleotromagnet may 'be of the single coil type or of the double coil type. When the electromagnet l5 is of the double coil type, one coil serres as the energizing winding for attracti g the armature to its energized position, and `one other coil functions as a sealing or lock-up coil which servos to electrically lock up the relay energized position by maintaining the electromagnetic attraction, even though the circuit through the energizing coil or pickup coil has een interrupted. When the eleotrornagnet is the single coil type, the terminals of this single oil are soldered to one pair of the ter: ual tabs :15h or 65h, and when the eleotrornagnet is of the ooubie coil type, the other coil has its terminals -dered to the other pair of these terminal tabs. -/ly improved relay can also be constructed of latching type, such as I have shown in Fig uref; 22 and 23. ln. this construction, the upper lo mounting brackets fl'l and de are made substantially longer so as to mount another electroinagnet Mb and armature it@ directly in back of the inain electromagnet i5 and main armature This r armature constitutes a latch The main armature it cs a latching arni Mil secured thereto and er.-

ding rearwardly across the top of the upper ounting bracket fil. This latohing arm iti' is provided at its front end with a downturned which is secured by screws i535 to the front side of the main armature lle, whereby a standconstruction of electiornagnet and armature suo-assembly t5, it can be used in this latching type of relay, the latching arm lill being a mere attachment secured to the regular design of armature The subeasserobly releasing eleetroniagnet.

ille can be made iden tical with the sub-assembly 5, t5, except sub-assembly let is mounted in inverted position the armature hinge at the bottom, Secured to the upper swinging end oi the armature it@ is a latohing dog M5, this a se; arate attachment adapted to be secured to the regular design of armature by the attaching screws ibi rlhe latching dog lila extends upwardly through a output opening ibi? punched out of the web of the upper mounting bracket di. lunched down out of the end portion oi the latching arrn it? is a lug i533 which as stop lug for limiting the forward spring return. movement of the latching armature leb. The parts are shown in the latched position the relay. The main armature it has been moved into its rearward position oy the energizaticn of the eleotrornagnet and this has caused the latching arm lill to swing upwardly a position where the latching dog M9 can snep in under the of the latch arno lill. ence, the main arfnature it will, remain in its ition, with the movable transfer the rearward stationary latched relation will the releasing electromagnet leb is tracto-el rearwardly, thereby snapping f: og Mt out fron` under the rear end ing arin i and permitting the main to swing forwardly to its normal reein. lin all other respects, this latching type oi relay shown in Figures 22 and 23 is i4 the same as the lsingle coil and double coil types previously described in Figures l to 2l, inclusive.

While I have illustrated and described what I regard to be the preferred embodiments ci any invention, nevertheless it will be understood that such are merely exemplary and that numerous modincations and rearrangements may be made therein without departing from the essence of the invention.

l claim:

1. In a relay adapted for plugin mounting in a panel, the combination or a mounting trarne adapted to be secured to 'the panel, said mountn ing frame having an opening therein adapted to Abe aligned with an opening in the panel, a relay frame adapted to be mounted on said mounting frame, sealing surfaces establishing' a dust-tight joint between said relay frame and mounting frame, cooperating movable and. stationary Contacts carried by sai-d relay trarne in position to extend substantially parallel with the iront face of the panel in the mounted position of the relay on the panel, plug-in soc ets carried by one of said frames and cooperating pluffon prongs carried by the other of said frames for reception in said plug-in sockets, said prongs and sockets dening a plane of support for said. roley franse extending substantially parallel to said panel, and an eleotroinagnet and armature for actus` ting said movable contacts carried by said relay frame and extending rearwardly beyond said dust-tight joint and beyond said plane of support and through said openings in the mounting frarne and panel in the mounted position of the relay on the panel.

2, n a relay adapted for panel mounting, the combination of a socket frame adapted to be secured to a panel, said socket frame having an opening therein adapted to be aligned with an opening in the panel, sealing surfaces establishm ing a dust-tight joint between said socket frame and said panel, a relay to be mounted on said socket traine, sealing surfaces establishing a separable dust-tight between said relay frame and said socket trarne, cooperating movable and stationary contacts carried by said relay frame in position to extend substanm tially parallel with the front face of the panel in the mounted position of the relay on the panel, an electro-magnet and an armature responsive thereto carried by said relay frame for actuel@ ing said movable contacts, plugoin prongs elec trically connected with said contacts and with said electromagnet and projecting rear erdly from said relay frame, and plug-in sockets in said socket frame adapted to receive said plugin prongs when said relay frame is mounted in seid socket fra-ine, said electroniagnet extending rearwardly beyond both said dust-tight joints and through said openings in the soclret trarne and panel in the mounted position of the relay on the panel.

In a relay adapted for plug-ln mounting in a panel, the combine tion of a mounting frame adapted to be secured to a panel, said mounting frame having an opening extending therethrough adapted to be aligned with an opening extending through the panel, a relay traine adapted to have plug-in mounting on mounting coaoting sealing surfaces on said relay trarre and on mounting frame establishing a separable dust-tight joint therebetween, cooperating movable and stationary contacts carried by said relay trarne, .a substr` ntially dust-tight sight window in the front of said relay frame through which said contacts can be inspected from the front side of the panel when the relay frame has its plugged-in mounting on said mounting frame, an electro-magnet and an armature responsive thereto for actuating said movable contacts carried by said relay frame, said electromagnet and armature mechanism projecting in a rearward direction from said contacts and from said sight window and adapted to extend back through said aligned openings in the mounting frame and panel in the mounted position of the relay on the panel, and cooperating plug-in prongs and plug-in sockets carried by said two frames and adapted to have plug-in reception when seid relay frame is mounted on said mounting frame, said electromagnet extending rearwardly of the plane oi said plug-in prongs and sockets and rearwardly of the plane of said `separable dust-tight joint in the mounted position of said relay on the panel.

4. In a relay of the class described adapted for plug-in mounting in a panel, the combination of a mounting frame adapted to be secured to a panel, said mounting frame having an opening extending therethrough adapted to be aligned with an opening extending through the panel, a relay frame adapted to have plug-in mounting on said mounting frame 2nd comprising front and rear insulating frame sections, a sight window opening extending through said frame sections, a bank of movable transfer contacts secured between the upper portions of said frame sections 2nd extending downwardly into said sight window, front and rear banks of stationary contacts secured between the lower portions of said frame sections and extending upwardly into said sight window on the front and rear sides of said transfer contacts, contact actuating means operatively connected with said. movable transfer contacts and extending rearwardly therefrom, an armature arrrnged to operate said contact actuating means, an eleetromagnet secured to said rear frame section projecting rearwardly therefrom for operrting said armature, plug-in sockets carried by said mounting frame, and plug-in prongs projecting rearwardly from said rear relay frame section for reception in said plug-in sockets, said plug-in prongs and plug-in sockets deiining a plane of support for said relay frame extending substantially parallel to said panel when said relay frame is plugged into said mounting frame, in which position said electronic gnet extends through the aligned openings in said mounting frame and panel and rearwardly of said plane oit support.

5. In a relay of the Vclass described adapted for a plug-in mounting in a penel, the combination of a socket frame adapted to be secured to the panel, said socket frame having an opening extending therethrough adapted to bey aligned with an opening extending through said prnel, a relay frame composed of insulation comprising front and rear frame sections, a sight window extending through said frame sections, a transparent pane closing the front side of seid sight window, a bank of movable transfer contacts secured between said front and rear relay frame sections and extending into said sight Window, front and rear banks of stationary contacts secured between said front and rear relay frame sections and extending into said iront window on the front and rear sides of said movable transfer contacts, a contact actuating bracket connected with said movable transfer contacts, said bracket projecting rearwardly from Said i6 bank of transfer contacts, an armature arranged to actuate said bracket, an electro-magnet secured to the rear side of said relay frame and projecting substantially horizontally rearwardly therefrom, said electro-magnet operating said armature, plug-in prongs projecting rearwardly from said rear relay frame section and operatively connected with said contacts and with said electro-magnet, and plug-in sockets in said mounting frame adapted to receive said relay prongs, said electro-magnet extending rearwardly of the plane of said plug-in prongs and sockets and rearwardly through the aligned openings in said socket frame and in said panel in the mounted position of the relay on the paneLwith said front and rear' frame sections being the only part of said relay extending forwardly from said panel.

6. In a relay of the class described, the combination of an insulating relay frame comprising front and rear frame sections, a sight window extending through said frame sections, a bank of movable transfer contacts secured between said frame sections and extending into said sight window in one direction, front and rear banks of stationary contacts secured between said front and rear frame sections and extending into said sight window from another direction, a spacing block of insulating material disposed between said front and rear banks of stationary contacts, said latter contacts being disposed on the front and rear sides of said movable transfer contactsJ an insulating bridge member operatively connected with said movable transfer contacts, an armature to which said bridge member is secured, an electro-magnet to which said armature responds, bracket means securing said electromagnet to said rear frame section with the electro-magnet projecting rearwardly therefrom, plug-in prongs bent laterally irom the ends of said transfer contacts and stationary contacts and projecting rearwardly from said rear frame section, and a mounting frame in which said relay frame is adapted to have plug-in mounting, and plug-in sockets in said mounting frame for receiving the plug-in prongs of said relay frame, said mounting frame having an opening therein through which said electromaenet is adapted to extend in the mounted position of said relay frame in said mounting frame, with said front and rear frame sections of the relay frame beine' the only parts of said relay extending forwardly from said mounting frame.

'7. In a relay of the class described, the coinbination of a bank of movable contact fingers, a bank of stationary contacts cooperating with said movable contact fingers, a relay frame on which said movable contact fingers and stationary contacts are supported, an armature connected to actuate said contact fingers, an electromagnet for actuating said armature, said electromagnet comprisingr a magnetic frame, a mounting bracket on which said armature has pivotal mounting, first adjustable securing means for adjustably securing said armature mounting bracket to said magnetic frame of the electromagnet whereby the armature mounting bracket and armature can be adjusted relatively to said electromagnet and said magnetic frame, and second adjustable securing means for adjustably securing said magnetic frame of the electromagnet to said relay frame whereby said electromagnet and armature can be adjusted as a unit relativelyto said movable contact fingers, said first adjustable securing means being carried by said magnetic frame to move therewith in the adjustments of said magnetic frame effected by said second adjustable securing means.

8. In a relay adapted for mounting on a panel or the like, the combination of a relay frame, cooperating movable and stationary contacts carried by said relay frame in position to extend substantially parallel with the front face of the panel in the mounted position of the relay on the panel, an armature connected to actuate said movable contacts, an electro-magnet for actuating said armature, said electro-magnet comprising a magnetic frame, a mounting bracket on which said armature has pivotal mounting, adjustable securing means for adjustably securing said armature mounting bracket to said magnetic frame of the electro-magnet whereby the armature mounting bracket and armature can be adjusted relatively to said electro-magnet and said magnetic frame, and adjustable securing means for adjustably securing said magnetic frame of the electromagnet to said relay frame whereby said electromagnet and armature can be adjusted as a unit relatively to said movable contact fingers, said first adjustable securing means being carried by said magnetic frame to move therewith in the adjustments of said magnetic frame effected by said second adjustable securing means.

9. In a plug-in type of relay adapted for panel mounting, the combination of a socket frame adapted to be secured to the panel, said socket frame having an opening extending therethrough adapted to be aligned with an opening extending through said panel, plug-in sockets provided in said socket frame, a plug-in relay comprising a relay frame carrying plug-in prongs adapted for reception in said plug-in sockets, stationary and movable contacts carried by said relay frame electrically connected with said plug-in prongs, and an electromagnet and an armature carried by said relay frame for actuating said movable contacts, said plug-in prongs and plug-in sockets defining a plane of support for the relay frame extending substantially parallel to said panel when the relay is plugged into said panel, in which position said electromagnet extends through the aligned openings in said socket frame and panel and rearwardly of said plane of support.

10. In a plug-in type of relay adapted for panel mounting, the combination of a socket frame adapted to be secured to the panel, said socket frame having an opening extending therethrough adapted to be aligned with an opening extending through said panel, a plug-in relay comprising a relay frame adapted to be mounted on said socket frame, plug-in sockets provided in one of said frames, plug-in prongs carried by the other of said frames adapted for reception in said plug-in sockets, stationary and movable contacts carried by said relay frame adapted to be electrically connected to said plug-in prongs and sockets, and an electromagnet and an armature carried by said relay frame for actuating said movable contacts, said electromagnet extending through the aligned openings in said socket frame and panel when said relay is plugged into said panel.

HAROLD E. S-EATON.

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